In grocery shops selling edible products, such as meat, fish, fruit, vegetables etc., it is a well known challenge to dispose of products that are overdue as regards final date for selling or which have decayed in quality. Not only the volume, but also any smell, moisture and commenced deterioration caused by bacteria, fermentation and/or fungi are severe environmental problems. Also there is a high risk of attracting mice and rats or other harmful creatures. To a certain extent, public sanitary services provide regular collection and can transport to an incineration plant or a biogas plant, but the waste is often smelly and wet, yielding dripping from the collection container.
However, treating products like these may in some circumstances present health hazards to personnel handling such goods. Further, many such products are associated with packaging such as e.g. sheet metal boxes, metal or plastic lined containers, plastic, cardboard, cellulose-based or corn-flour based trays, cling film or blister-packs. It is also a challenge that it is a time-consuming and sometimes indeed a messy job to remove packaging for source-type sorting.
Not only in grocery shops, but also in catering activities, hotels, restaurants, public health institutions (e.g. hospitals or old-people homes), onboard ships and offshore installations, and collection services from trains and aircrafts, handling of waste in a hygienic way is a daily and serious challenge.
In this context it is important to be able to reduce the volume and weight of substance(s) and produce a dried end product material which is substantially homogeneous per unit volume and is hygienic in accordance to laws and legislations, i.e. by EU. Volume is suitably reduced through fragmentation. However, it is a challenge with prior art shredders to obtain satisfactory fragmentation of e.g. grocery substance(s) and wrapping or packaging related thereto. This challenge is dealt with in the second aspect of the invention.
In the context of the first, third, fourth and fifth aspects of the invention, there is in the prior art known numerous devices for mixing and/or fluidizing particles or fragmented substances, or fluidizing at least one fragmented substance. Such devices are at least partly described in inter alia the Norwegian patent applications 19890434, 19905274 (=NO-patent 176552), 19931642 (=NO-patent 177415 or U.S. Pat. No. 5,984,520 or EP-patent 0738182), 19952255 (=PCT-publication WO96/404422), 19971044 (=NO-patent 306242), and 20021512.
Further, a method and a plant for pre-treatment of source separated wet organic waste is known from Norwegian patent application 20035803 (=WO2005/061114-A1). Another reference is an article entitled “Microbial Inactivation during Superheated Steam Drying of Fish Meal” by Halvor Nygaard and Oistein Hostmark”, Drying Technology, 26:222-230, 2008; URL: http://dx.doi.org/10.1080/07373930701831648